function eid(ele) {
  return document.getElementById(ele);
}

function 选择(选卡) {
  eid("语文科").style.color = "#ccc";
  eid("数学科").style.color = "#ccc";
  eid("英语科").style.color = "#ccc";
  eid("政治科").style.color = "#ccc";
  eid("历史科").style.color = "#ccc";
  eid("物理科").style.color = "#ccc";
  eid("体育科").style.color = "#ccc";
  eid("主内容").style.left = (选卡 - 1) * -110 + "%";
}
